Ball point pen

ABSTRACT

A pressure ball point pen which comprises a ball point means, a writing ink reservoir means, an air pressure chamber and an end closure means. A pressurized air is contained in the air pressure chamber by the end closure means adapted to be forced into the end of the air pressure chamber or by means of an outer sleeve adapted to sheathe the writing ink reservoir means.

United States Patent [1 1 Tsunoda et a1.

BALL POINT PEN Inventors: Norimasa Tsunoda; Tsutomu Saito,

both of Yokohama, Japan Filed: Oct. 27, 1971 Appl. No.: 193,020

Foreign Application Priority Data Nov. 6, 1970 Japan..... 45/109547 (utility model) June 21, 1971 Japan 46/43960 (utility model) Apr. 15, 1971 Japan 28,337 (utility model) US. Cl 401/190, 53/37, 401/141, 401/142 Int. Cl B43k 7/10 Field of Search 401/188, 190, 217, 401/141,142, 187

References Cited UNITED STATES PATENTS 4/1964 Eckerle 401/190 X FOREIGN PATENTS OR APPLICATIONS 624,703 9/1961 Italy 401/141 1,159,103 2/1958 France 401/142 Primary Examiner-Lawrence Charles Attorney-Ernest A. Greenside [57] ABSTRACT A pressure ball point pen which comprises a ball point means, a writing ink reservoir means, an air pressure chamber and an end closure means. A pressurized air is contained in the air pressure chamber by the end closure means adapted to be forced into the end of the air pressure chamber or by means of an outer sleeve adapted to sheathe the writing inlc reservoir means.

1 Claim, 7 Drawing Figures PATENIEU NOV 2 7 I9?5 SHEET 10F 2 FIGZ FIG]

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PATENTH] "BY 27 I975 3. 775 O15 SHEET 2 BF 2 74 6 76 FIG. v 72 1 v 64 I 70 ENToRs ORIMASA TSUNOU TSUTOMU SAITO BALL POINT PEN BACKGROUND OF THE INVENTION This invention relates to a ball point pen which accomodates a compressed air chamber adapted to facilitate the smooth discharge of the writing ink and a method of manufacturing such the pressure ball point pen.

It is known to increase an atmospheric pressure within the writing ink reservoir of the ball point pen so that the ink of high concentration and viscosity may be utilized without causing any dripping or leakage of the ink and rather enabling the user to write in the upward direction of the ball point means.

The pressure ball point pen of this type heretofore used has an intricate construction including an example means for receiving the chemical substances adapted to generate a high pressure gas which usually require an expensive manufacturing cost.

SUMMARY OF THE INVENTION viate any difficulty and inconvenience in the conventional ball point pen and provide an improved pressure ball point pen of simple construction which provides an easy manipulation and reduces the manufacturing cost considerably.

In one aspect of the invention, an elongated ink reservoir having at its one end a ball point means is filled with the writing ink from the opposite end thereof which is then sealed in an air-tight manner by a closing plug means to form a compressed air chamber between the ink surface and the closing plug means.

An object of the present invention is to provide a pressure ball point pen which comprises an elongated ink reservoir containing the writing ink, a ball point means secured to one end of said elongated ink reservoir and an end closure means forced into an opposite end of said elongated ink reservoir in an air-tight manner to provide a compressed air chamber between the ink surface and said end closure means.

In another aspect of the invention, an inner ink reservoir having at its one end a ball point means is filled with the writing ink and from the opposite end thereof sheathed in an air-tight manner by an outer sleeve through an elastic ring encircling the said inner ink reservoir to provide a pressed air chamberfor compressing the ink under the desired pressure for the purpose of continuous smooth writing.

Another object of the invention is to provide a pressure ball point pen which comprises an elongated inner ink reservoir, a ball point means secured to one end of said inner ink reservoir, an elastic ring means encircling said inner ink reservoir and a bottomed outer sleeve sheathing in an air-tight relation said inner ink reservoir from an opposite end thereof to provide a compressed air chamber in abutment with the ink.

In a further aspect of the invention, an ink reservoir having at its one end a ball point means is filled with the writing ink and the opposite open end of the ink reservoir is closed in an air-tight manner by a sealing plug having vertical groove for a compressed air inlet and adapted to be welded to the open end of the ink reservoir to provide a compressed air chamber between the ink surface and the sealing plug. l

A further object of the invention is to provide a pressure ball point pen which comprises an elongated ink reservoir, a ball point means secured to one end of said ink reservoir and an end closure means having a vertical groove for compressed airtinlet and inserted into the opposite end of said ink reservoir in a welding manner to provide a compressed air chamber between the ink and the end closure means.

A pressure ball point pen of the above third embodiment may be prepared by an apparatus in accordance with the invention in such a way that an open end of the ink reservoir containing the writing ink and having a ball point means at its opposite end is inserted into a high pressure gas chamber of the apparatus and closed by a closing plug of heat fusible material having a vertical groove for air inlet and then compressed air is supplied into the high pressure gas chamber from the supply source and subsequently into the space formed between the ink and the closing plug through the air inlet groove provided in the plug and finally the ultrasonic oscillation is transmitted through an oscillator to the plug for thermal welding with the open end of the ink reservoir thereby to provide a compressed air chamber between the ink and the end closure plug.

Still a further object of the invention is to provide a method of manufacturing a pressure ball point pen which comprises filling an elongated ink reservoir having at its one end a ball point means with the writing ink, closing an opposite open end of said ink reservoir by an end closure member of heat fusible material, subjecting the end closure member to an ultrasonic oscillation for welding attachment with the open end of the ink reservoir thereby to provide a compressed air chamber between the ink surface and the end closure member.

Yet a further object of the invention is to provide an apparatus for manufacturing a pressure ball point pen which comprises a base body, an elastic holding mass member accomodated in the base body and provided with an aperture for supporting an open end portion of elongated ink reservoir and a high pressure gas chamber, an ultrasonic oscillation means disposed in the base body in alignment with the aperture for transmitting an ultrasonic oscillation to an end closure member inserted into the open end of the ink reservoir and a path disposed above the ultrasonic oscillation means and communicating into the high pressure gas chamber.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS For a fuller understanding of the nature and object of the invention a reference should be had to the following detailed description taken in connection with the accompanying drawing:

FIG. 1 is a vertical view partially in sectioned of the ball point pen in accordance with the invention;

FIG. 2 is a pictorial elevation of an end closure memher before being inserted into an open end of the ink reservoir;

FIG. 3 is a longitudinally sectioned view of another embodiment of the ball point pen in accordance with the present invention;

FIG. 4 is a pictorial elevation of the ball point pen of FIG. 3 showing an outer sleeve before air-tight engagement with an inner ink reservoir; I

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now in more detail to the drawings, wherein like parts are indicated by like reference numerals and initially to FIG. 1, there is illustrated therein longitudinally sectioned view an elongated writing ink reservoir tube of the ball point pen made of steel,

hard vinyl chrolide and other suitable materials and secured at its one end with a ball point 12 with the writing ink 14 received therein.

Into the opposite end of the reservoir 10 an end closure member or airtight plug 16 is forced to provide a compressed air chamber 18 under the desired pressure of approximately 2 atms. The airtight plug 16 comprises a support arm 20 provided at its one end with a sealing member 22 of rubber and other suitable material having a diameter of approximately from 0.5 to 1mm greater than the inner diameter of the ink reservoir and at its opposite end with a closing member 24 with a head rim 26.

After the airtight plug 16 has been completely inserted into the open end of the ink reservoir 10 under the pressure, a circumference adjacent the open end of the reservoir tube 10 is somewhat depressed inwardly to form an annular channel 28 for air-tight seal with the closing member 24 of the plug 16.

Outer circumferential surfaces of the sealing member 22 and the closing member 24 may be applied with grease or putty to minimize a friction with an inner circumferential wall of the ink reservoir on insertion and to prevent any leakage of the compressed air from the chamber 18.

The support arm 16 and the airtight seal member 22 may be fixed to the inner circumferential wall of the reservoir tube 10 by a suitable bond when desired.

In case the inner diameter of the reservoir tube 10 exceeds 3mm, a movable plug 30 having approximately 0.2mm smaller diameter than the inner diameter of the reservoir tube 10 and less specific gravity than the writing ink in the reservoir may be floated in the ink surface to check the counter flow of the ink.

In the embodiment shown in FIGS. 3 and 4, an elongated inner ink reservoir 32 made of steel or other suitable synthetic material is provided with a ball point 34 at its one end and the opposite end thereof is left in open.

The inner ink reservoir tube 32 at its proper circumferential portion is somewhat depressed inwardly to form an annular channel 36 along which an elastic annular ring 38 is encircled as best shown in FIG. 3. The elastic annular ring 38 is preferably made of rubber or synthetic resin.

The elongated inner ink reservoir 32 is filled with the writing ink leaving the upper portion in vacant to provide a pressure chamber 40 as hereinafter described.

The open end of the inner ink reservoir 32 is inserted into an outer sleeve 42 of somewhat larger diameter than the outer diameter of the reservoir and having a closed bottom end and when the annular ring 38 is forced into the outer sleeve 42, an air flow from the reservoir tube is completely confined and the pressure in the pressure chamber 40 is raised to approximately two atms by sliding the inner reservoir upwardly. It will be appreciated that the annular ring 38 should be properly positioned to keep the pressure in the pressure chamber 40 at approximately two atms.

As best shown in FIG. 3, an open end of the outer sleeve 42 is somewhat bent inwardly to make a fixed engagement with a shoulder portion 44 of the ink reservoir. Alternatively, the open end of the outer sleeve 42 may be provided with a threaded portion or other suitable fixing elements so that the inner reservoir 32 after the ink therein worn out may be replaced by a fresh reservoir containing the ink. It will be also possible to construct the outer sleeve so as to compress the gas in the pressure chamber when using the pen while to keep the pressure chamber at relatively low pressure when the pen is not used for writing purpose thereby to prevent any leakage of the ink.

FIG. 5 shows another embodiment of the ball point pen according to the invention, wherein an open end of the ink reservoir 46 is closed by an airtight plug 48 of heat fusible material such as vinyl chloride and the details of closing operation will be described hereinafter.

As best shown in FIG. 5, the airtight plug 48 comprises a head rim 50 integrated with a stem 52 and an extended leg 54 and provided with one or more vertical groove 55 which extends from the tip of the leg 54 to the position at least across the stem 52. The open end of the ink reservoir tube 46 is interiorly provided with a stepped portion 56 adapted to receive the stem 52.

In FIG. 6, an apparatus for manufacturing the ball point pen illustrated in FIG. 5 is constructed of a base body 58 which accomodates an elastic support member 60 having an aperture 62 for supporting an open end portion of the ink reservoir tube 46.

The elastic member 60 is further provided with a recess 64 which provides a high pressure chamber 66 when the elastic member 60 is united with the base body 58.

The base body 58 further accomodates an ultrasonic oscillator 68 disposed in alignment with the aperture 62 and one end of the ultrasonic oscillator 68 is exposed into the high pressure gas chamber 66 in opposite relation with the head rim 50 of the air-tight plug 48. Above the ultrasonic oscillator 68 is provided a pressurized air path 70 communicating at its one end into the high pressure gas chamber 66 and communicated at its opposite end with a pipe 72 connected in turn to a solenoid valve 74 and a pressure gauge 76.

In operation, the open end of the ink reservoir tube containing the writing ink is mounted in the aperture of the elastic support member and then the airtight plug is inserted into the open end portion so that the head rim of the airtight plug confronts with the end of the oscillator. In this condition, the solenoid valve is opened to supply the dehydrated air or other suitable inert gas at a suitable pressure into the high pressure gas chamber. The gas is further supplied into the space formed between the ink surface and the closing plug through the vertical groove provided in the closing plug. Thereafter, the oscillator is moved toward the head rim of the plug for compression and simultaneously an oscillation is applied thereto to transmit the oscillation to the contacting portions between the plug and the open end of the ink reservoir so that the heat is generated therebetween with fusing of the plug member. The fused material is penetrated into the vertical groove of the airtight plug resulting with an intimate fixation of the closing plug with the open end of the ink reservoir thereby to provide the compressed air chamber at the end portion of the ink reservoir. These operations including from the opening of the solenoid valve to the finishing may be accomplished in a second.

In accordance with the ball point pen of the present invention, a compressed air of desired pressure may be sealed into the ink reservoir in a simple and effective manner for the purposes of smooth and extended writing by the user without following any leakage of the ink.

While certain preferred embodiments of the invention have been illustrated by way of example in the drawings and particularly described, it will be understood that modifications may be made in the constructions and that the invention is no way limited to the embodiments shown.

We claim:

1. A ball point pen comprising an elongated ink reservoir terminating at one end in writing means and at an opposite end in an opening, a supply of ink within said reservoir to a level below its open end, and an end closure of heat fusible material for said open end and serving to limit one end of a solely fluid filled, fluid pressurized, chamber delimited at its opposite end by said ink level, said end closure comprising an enlarged head portion having an outer end face and an axially extending stem portion projecting from an inner face of said enlarged head portion opposite said outer face into said reservoir, said stem portion being formed throughout its length with at least one longitudinally extending groove terminating inwardly of said outer face of the head portion, said end closure having first and second positions in relation to said reservoir, said inner face of the enlarged head portion in said first position of said closure being spaced from the open end of said reservoir with its stem portion and groove therein at least partially introduced within said reservoir and being in sealing engagement with the reservoir open end in said second position of the closure, and an external source supplied fluid in said reservoir supplied therein via said longitudinally extending groove in said first position of said end closure and during positioning thereof to said second position in which said groove is wholly within said reservoir and sealed against communication with the atmosphere. 

1. A ball point pen comprising an elongated ink reservoir terminating at one end in writing means and at an opposite end in an opening, a supply of ink within said reservoir to a level below its open end, and an end closure of heat fusible material for said open end and serving to limit one end of a solely fluid filled, fluid pressurized, chamber delimited at its opposite end by said ink level, said end closure comprising an enlarged head portion having an outer end face and an axially extending stem portion projecting from an inner face of said enlarged head portion opposite said outer face into said reservoir, said stem portion being formed throughout its length with at least one longitudinally extending groove terminating inwardly of said outer face of the head portion, said end closure having first and second positions in relation to said reservoir, said inner face of the enlarged head portion in said first position of said closure being spaced from the open end of said reservoir with its stem portion and groove therein at least partially introduced within said reservoir and being in sealing engagement with the reservoir open end in said second position of the closure, and an external source supplied fluid in said reservoir supplied therein via said longitudinally extending groove in said first position of said end closure and during positioning thereof to said second position in which said groove is wholly within said reservoir and sealed against communication with the atmosphere. 